/* 
 * Copyright (c) 2004-2005 Massachusetts Institute of Technology. This code was
 * developed as part of the Haystack (http://haystack.lcs.mit.edu/) research 
 * project at MIT. Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation files (the 
 * "Software"), to deal in the Software without restriction, including without 
 * limitation the rights to use, copy, modify, merge, publish, distribute, 
 * sublicense, and/or sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following conditions: 
 * 
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER  
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE. 
 */
/*
 * Created on Sep 6, 2004
 *
 */
package jiggle.relo;

import java.util.Set;

import jiggle.Cell;
import jiggle.ForceLaw;
import jiggle.Graph;

/**
 * This force law models an infinite amount of friction on the given cells,
 * thereby not moving the cells by jiggle
 * 
 * @author vineet
 * 
 */
public class InfiniteFrictionLaw extends ForceLaw {

    private final Set<Cell> oldCells;

    /**
     * @param graph
     * @param oldCells
     */
    public InfiniteFrictionLaw(Graph g, Set<Cell> oldCells) {
        super(g);
        this.oldCells = oldCells;
    }

    @Override
    public void apply(double[][] negativeGradient) {
        int nv = graph.getNumberOfVertices();
        int nd = graph.getDimensions();
        //int ne = graph.numberOfEdges;

        for (int i = 0; i < nv; i++) {
            Cell curCell = graph.vertices.get(i);
            if (oldCells.contains(curCell)) {
                for (int d=0; d<nd; d++) {
                    negativeGradient[curCell.gradientNdx][d] = 0;
                }
            }
        }
        
    }


}